Radio receiving system



March 22, 1932. F. SCHRTER 1,850,569

RADIO RECEIVING SYSTEM Filed June l1, 1928 F nz 'scHRoTER ,az/W

TORNEY Patented Mar. 22, 1932 UNITED STATES PATENT orFrcE y FRITZ SCHRTER, OF BERLIN, GERMANY, .ASSIGNOR TO TELEFUNKEN GESELLSCHAF'J.`

FR DRAHTLOSE TELEGR-APHIE M. B. HK.,

GERMANY OF BERLIN, GERMANY, A CORPORATION OF RADIO RECEIVING SYSTEM Application led .Tune 11, 1928, Seria! No. 284,286, and in Germany .Tune'25, 1927. f

It is knowny from practical experience that, apart from the signals directly received at the receiving station `from the transmitter, the same signals vare coming in at the receiving station one or more times according to whether t-hey travel one'or more times around the earth, with the result that normal operation and traiiic is disturbed. In order to `obviate trouble of lthis kind the suggestion has been made V-to sendout at the transmitter station the consecutive signals or signalgroups at different frequencies" (carrier waves or modulation waves), andto change at the receiving station the selectiveV means in accordance `with the frequency changes at the transmitter station and to separate or filter out the signals by other means. In a method of this kind, the energy of the signals coming in at the kreceiving station after having passed around the earth repeatedly goes to waste.

The present invention has for its principal object thatfot disclosing a method whereby also the energy of incoming signals are utilized aftert they have traveled around the earth. The kmethod here to be specified may be utilized whenever a signal system is employed wherein the constituent signals are of like duration, as, for instance, in commimication by means of the so-called tive-unit code or a similar code.

The invention consists in that the directly arriving signals are not used at once for influencing the indicator instrument, but that the electrical or magnetic actions produced thereby are first integrated with or added to the actions produced by recurring signals, whereupon such integrated action is caused finally to iniluence the indicator.y

The basic idea of the invention shall be eX- plained by the aid of the practical example shown as a single figure in the accompanying drawing. The lett-hand side of the figure shows diagrammatically a sending station, while a receiving station is shown on the riglitshand side. The two contact arms or wipers 1 and 11 run 'in synchronism so that they'are practically at the same instants (save tor the time,A required for the propagation of the wave from the sender to the' receiver sta- 0 tion) in the same quadrants I, II, III or IV impulses accordingto the signals. The number 5 chosen in the example would correspond to the tive-unit code, so that, according'to the particular segment among the five segments to which the impulses of a signal are supplied, different letters will be produced, it havingto be noted, however, that when using the veunit code, the number of the said segments may also be a multiple of five, as will be readly understood from .what follows further beow. Y

The currents iiowing through the diiierent segments according to the particular positions of contact arm or wiper 11, and being rectified by the receiver are supplied to the various storing or integrating condensers 12, 13, 14, 15 and 16. After passing over the first quadrant no further impulses shall for the time being be supposed to be transmitted Jfrom the transmitter. After completecirculation around the earth, the signals recur or are repeated at the receiving station at a time when the contact arm or wiper closes the contacts f, g, 7L, z', 7a of the quadrant II. These direct current impulses, as can be seen from the drawing, are fed to thesame condensers as before. While the wiper passes over the segments'l, m, n, 0, p, of quadrant III, such signals as are coming in after another circulation around the earth will again be fed to the same condensers. In quadrant IV by means of the contacts on segments g, r, s, t, u, discharge of the condensers for lthe purpose ot signal indication or reading is eii'ected by the aid of change-over switch 19. The latter revolves in synchrouism with wiper 1, and while the quadrants I, II and III are being passed, it has conducted the currents ed at 17 by way ot segment 18 and wiper 19 to the condensers, whereas in its position at quadrant IV, it conducts the discharge currents of the condensers successively by way OtsegkInent 20 Vand the relay Winding 2l. This relay actuates an indicator', which, for instance, may be of'th'ekind resembling a printing mechanism as in the Siemens high-speed telegraph, although it will be understood that also some other recording devices based upon the photographic principle could he used.

In order that, contradistinct from the casey l just examined, the complete ,time of rotation ofyvi er "1' atthe transmitter end may be*-uftil,` i ized or signal transmission, themethod may be modified in so far as at the sending endI the frequency whereby the signalsfare sent tout, that is tosay, either the carrier Wave or the modulation frequency, is altered so that' in quadrant A,I the frequency generated by gen.-

erator 6y is w1,.inq,uadrant II the frequency generted bythe generator 7 is a02; in quad? rant VII[ :the .frequency is w3 and producedy by generator Spin.V quadrant IV the frequency w4is generatedby generator 9with the re.- sult that,y whilethe Wiper 1. passes over Vthe Y segments 2, 3?, lLand. 5, transmission of imcei'vers I, II, IIIv andIVtuned to. thek differ.-

ent- Wajves.A In this scheme, for instance, the

secondf signal which arrives at the receiving station on a different Wave,-length.will be receivedor recorded or utilized for charging the cor-responding;condensers at a time when the. first indicator means haspnot yet been operated, hence, the Whole time is utilizedrfor. signal transmission.

i Having thus described my invention, I claim y V1. Alsystem for 'receiving Wireless signals andthe like.` of equal durationv including, means. for receivingl signals directly and in.- directl'y from, a transmitting station, means for storingup the direct and indirect signal energy to produce! a combined signal effect substantially equal to the sumo all the signal? ei'ects", and indicating means for utilizthe` stored up result of all of said signal effects.,v v i 2l Asystem fr receiving :Wireless signals of4 duration including, means for receiving a signal directly from a transmitting station andat a later period ottime receiving same signal.v indirectly fromthe same transmitting station, a plurality of capacity units: associated with saidl signal receiving means for storingthe combined signal energy receivedinsaid system,.means operable at a definite :period of time after the'A reception of saidvsignalsffor discharging the stored energy from said capacity units, and means associatedl withk said capacity. discharging means Vmeans provided by said last named distributing device forsupplying a charge to said 'capacity unit forsignals received die rectly fromvsaidtransmittingr station and at ay later. period ottime: supplying an additional lcharge to said capacityfunitsflforsig- Y nails received indirectly; yfrom said transmitting station, means associated with said distributor device for discharging the energy stored insaid capacity devices at predeterf mined intervals of time,"andsignalreeording means responsive to thefsaid discharged energyrfrom said capacity devices for producing a record of the said received. signals.

4:. A system forfreceiving, wirelesssignals yand ythe like of equal duration including, meansfor receivingf'signals directly and in,- directly from a rtransmitting sta-tion,.av plurality ofcapacity units for storing all of said receivedrsignal energy, means for controlling the period of time during lvvhichvsaid signal energy issupplied to said capacity, means for discharging said capacity unit during a fixed predetermined time ,and producing current pulses of duration correspondingto an integration of the combined receivedl signal effects'as stored in said capacity units, andsignal yreproducing means responsive kto said currenty pulses from, said capacity units for producing, an effect corresponding to the integratedell'ectof both directly and indirectly i received signals. v

5. A method of communication which consists in transmitting signals of equal duration, collecting original signal energy collecting recurringsignal energy, storingup the originalenergy adding thereto the recurring energy, and utilizingthe total energyy to record thev original,signals.., i

6.A A method of Wireless communication `which consists.. in transmitting signals of directlyfrom av transmitting station and, at

a later'period of time, indirectly from the same transmitting; station, means connected with the signal receiving means for storing the uncombined direct and indirect signal energy, means operable at a predetermined period of time after the reception of said signais for discharging the stored energy, and utilizing means connected yto said discharging means for recording the said signal energy.

FRITZ SCHRTER. 

